Could not the state intervene just as temporary guardian, to get the surgery done, then relinquish care back to the parents?
I suppose by doing so they risk the possibility of the parents failing to seek medical care for other serious things (diabetes, head trauma, cancer. . .)
on the other hand if the don’t they risk foster care, which is statistically very much not in most children’s best interest.
At the link there’s links to previous stories on this and other cases against members of the Followers of Christ Church.
The DA has tried working with them and sent letters to members re medical attention for minors with respect to OR law.
Some of the true believers won’t hear of compromise.